Modern data centers can have a huge number of individual computing servers, with some larger data centers having tens of thousands of computing servers or even more. Due to the large numbers of computing servers in modern data centers, those data centers consume an enormous amount of power. It has been estimated that current data centers are collectively responsible for consuming approximately 3% of the world's electricity, and it is estimated that the consumed power will double in the next five years. The cost of electricity is one of the limiting factors in the performance and profitability of a data center. Because of this, data center owners often wish to reduce their electricity usage while preserving the performance of their data centers.